SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bac25c745471d91b64e423a4a2c0baeea1c4d6009bc62cd2dcf6ff411a62a1e3' 
  AND token = 'rhhwR+rbODHPeKSKG8ZDXVFzIEBOXbk2Ku9hKdUrdIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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