SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd867eb8ae2a4d764c23626b1cc3a2193acac3800dcc38c58029a6d2148d73bd' 
  AND token = 'elPS6Xo2J6NgSX3iYbMvPbZHKZNhhlFRFRfXxvPEWzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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