SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b161494591cc034e2b192af2eeaeef24ba4ce721ecd6f90bd381529ee7bdb385' 
  AND token = 'GSmRaFe71rUEknGX/H9SoXA4r36At+3c0Hs0IWMqmeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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