SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95e270353d8ad450bf252cb64d26cb36a44099595f0efbf192e497cc18f72ac8' 
  AND token = 'gRcZuc1LoqhF+vwTimE3FbTwiQ/WM1Qa4BXKSO1uw8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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