SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d8d1bb88c6528f516ee4123901f6e719ed8450a053117dadf9b9df2f2b19377' 
  AND token = '0mCLbu+6tEnf1Y/aB5P0O9LKENY9KzeDL/N8yUfQ8mA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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