SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '755ebe060b4ef41b0f678ded226e544b22dee369ba343313722c265e77beec28' 
  AND token = 'rtGLRVbtoWRPurCXdly9ilvFEgI+76Z6c+hiBeCxQ3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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