SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1a94818ec6648830220b24ffe49051ca3dfe22d8bac608c760883e67da62f4b' 
  AND token = 'CK/xH0SkrsUrJizKs1EGBH6nprU+eqQrgkxdg4tPvVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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