SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93356f37d2d1c3240db91e29f8b475fcab7977e83e03e2f80228f717949d449b' 
  AND token = 'fNSPRk6BK9YWVXpBEGYsg+fI1hPMCDjdnLJMCaYq6Jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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