SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09347f294068c51778230cf70a3832524538f3f8bed345563d9e3aa6db4c9e9b' 
  AND token = 'WAdRcJod6ZMhO9ogCc1EgDJQEOA3PG+NQZjSYXeZeh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}