SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '54b746815a6b08f516d1852a614032bd13c926c8c599e19705bba79afa66cc3c' 
  AND token = 'fFS1qk2rz+hZGPWX7Sc0Kj1QVoXbFreFsCVzFGeWWus=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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