SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b039846245e08cb197df88cb26ede3a17becec2a071f007fb792f4ec02fe931e' 
  AND token = 'D7+jMEUMC2McoJGS9xfw8s1YPGcUWnJZmhESIGGzmqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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