SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79da94199dbd096020aa450907f7d8eb516056f9d17d64534334bff088b1c4d7' 
  AND token = 'yRq0XKgRrEdOVGWhREjxpF7hdodhCC8qkp+3LKxii48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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