SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a286ab3043ec0bfc4a61fa2eb1ea0dbb29346d7279935280953ca9fa0b2c7508' 
  AND token = 'SxdTejFL/qM7xVo1ToIAaCRUI8Q2/FO5U9fomYCJn+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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