Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b614eff9f50e61dadcdf8e886bf880c1a7994e3bf86ca528c59014aabad69fb6' 
  AND token = 'rt19+h/AKBmhH/FF3QEsWjdsDPPMJXtSl+SKMa4r7Ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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