SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cdb19ba776a0a1e48d22f4d334d45044cda2c7dfcb697b691cfc9b398505fe0' 
  AND token = 'UtZDTAvH52jg21OXvOSEvGgiDVbzJ3jhpSfIJmZsK4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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