SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad049586ccbcfdffa37b3980ea361f16c000daa6595a36eda7eeaf0de940ec86' 
  AND token = '68ZPLsAZFxS8JBLlqVR+GiO8egBH454o4RT/JOiUTe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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