SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a6dc657479f937976f8c6acd0118aa5df3c428d99b1767b2f316be0b00ef98f' 
  AND token = '+yef8WftwoIDN/nq7JEPsV2g5quFbxG+fkzJagmsBQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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