SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b773f3f683efd6286ee57780f1ce0cd1e86075c7039d7570409db120f258f49' 
  AND token = 'sr/VP/FDe/H2OBWwkamUGQ3/aCm4ir4/4oX0Rr44r+4=' 
  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