SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd89273b8564470cc45387b26621bcfc04cbb9ab5b489db701a8cd474774c792d' 
  AND token = 'EDb6h8mNXBFAUemhVCmUswzhS1NxVvDfPUA5BvbJQOA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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