SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44fa41b53a1343b09d6c25eeedd22bbeeb990fa9d187d7bdb051fc1a515bfc49' 
  AND token = 'hEnMieEUK4k5SM1vvSBKmUmMRehAMN3BTb+iN2u84sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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