SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b5322b13ac4c8e7b807cdeb6d1ef3cf2000438a7abfd9d18cfdfe846050a36c' 
  AND token = 'fL8C7vRRbNmQwNpFcJ9Syf++WuzUrPkNSx/x+bN2bEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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