SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bca27b0816c296aa1ea9f4250cef89e4b8ed9fe27dabb53f0085fd9b7031b599' 
  AND token = 'xn2wQZfaVcXmaZpStrqGkr8Vw2vbtjufdW92C+2D2pM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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