SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b083f3a71c351ae7ea7625b2e4a9723a967bddc5e6f57a31beb5a5330a7190af' 
  AND token = 'spczqysOAYN3NN0Natcr05KxjYHk1g5pY69xgG37/J0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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