SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d52e33160bdfa025803bd1cf2f27343146238eb101179bbfa7392b36d341a40' 
  AND token = 'MPIIP5no9sCE7ZWsnzcK5NYEPrvb4vEDG/uV0QjFTWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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