SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f59c6f0b7f86c8626aad0b11907a23906086ac5a20031466bc2c3840183caee7' 
  AND token = 'sNCODIeAIaeFL+vLOVbs7cKeDweDLfpDow17KhE1OCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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