SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32d7f51aa3b9b9f8c4db14da521fc9754242165701160be37aa3b50b446b75b6' 
  AND token = 'WEEQbmRve78BIfw5VhDrfnxJe4+hm0gQfmPspHjzit4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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