SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2aee6b2d660d8a517ecdf4ba4118edbf885bfa02b1c5a0d2cbbfc1a103df9c50' 
  AND token = 'rlTz5RZDie1XrpdbhypsTh9fIVfXJqeDFL08BiPaLSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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