SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '082d6ffaea68c916f492561171d3232ad546921f6976ef686ba7f59ad735a982' 
  AND token = 'DHGLSr7kiYewZPCVG3GlECIq+ZVJJ5nbwIn1EIjaLEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00075

JSON explain

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