SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a3bdba4be80aed14bc2d78f89f5a899819721729417db91eda1a7f2609ad3c8' 
  AND token = 'gyVvjJD/9+14IexSCIR8ymVTzz29GaAHA/modW6w4bM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables