SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a02416caa3bc051bf3227b8156d122c5c18e7210846dbb1f9c306f76956c5e61' 
  AND token = 'Qu1Oad+y4SRaUI6lCRgKhWZW2Dyrg0CxYM6OtxN4BLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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