SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2d6465800a0cbe813d27ef579d15544703fcae5a6f072c8153aceff637f42ac' 
  AND token = 'DL/jzlKCTuJJhLZ3QcGCqVV2VRfwoOpmLMC7KhUfLSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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