SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a09e637ccd32a5afa302b457048dd236358fb1e3da25f64814df90b0c853de32' 
  AND token = '6dGQjgPfXtDzhH3KTxrRu/SNSwqFa3e0+oP22SkElks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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