SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98932f6deab442653211fc487aa0212e15b9dc054e2b389f187a26137a9eccd9' 
  AND token = 'XVYpnXVY2krlMMRGeRe87gf0pEB2NiCjPSGTDeH9gO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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