SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1628337ae18d2959e7f9d835470cf8e09c4d6489fa0567c852724c1bbf40c368' 
  AND token = 'vfispXqgI0o+7Aw7/RtJlHyzKkPq2qqYnmoink1Nz/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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