SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '820d6e77b0ae34c347f2e2999cd45f298f4e267f03a3388e38d3adc007c7b353' 
  AND token = 'z5ZSYqqK5udUqufzYFUlduGdbaK84IK8gh1tTiIEcZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}