SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdfc5a0cb5dfdc3cc216f68355841a1bcfd2ce3f534d85721fb5a17d6f1f5181' 
  AND token = 'Otw8dY54dmtFU79ZJ2DdrG8i7rxMoQkAKBRZX4OLMns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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