SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9046788e93f4c32edb8bc1fa87adcad5efc9e506ba16d548668816173a4a4603' 
  AND token = 'BfmTYrc2nYptJAju0lci+4cukuX3OyloMtWETBLLrgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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