SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ade9d8a52bff7acb831843d066707062810f639a2b6e6712459651225855f745' 
  AND token = 'FtCtyWCJf1wF2lIZYXrD0pe4fPV6ZBakGPiMpZdIKNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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