SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8424d9a54580b3e59a621124d17a51d3541a03821d313fbf1a164666130166ce' 
  AND token = 'dhdEQxva4oYOxqIupz+Cl71d8E4VO4AsPqdjTnn08Fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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