SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3558d82702bc70df88360d6cf74b5f27a1a555cd364a4352de240e06f899b0b' 
  AND token = 'hbJfU4/BVKXJ3Wsw5xj3nFYmAo3qE5In+RRNON1E8Y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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