SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c56a5bbe48ed5fedf1c80ac0633b8cd9dfa68a150c0fb19af4c1b7884f910388' 
  AND token = 'nYj9LDKrZVTy807OmIQGZsK+MITGvdpdAhb5wKexV5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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