SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ae634964a93ee6854dd5125afa0e3b42a7e2749b55a6e0e8f55786501e638cc' 
  AND token = 'n1DObsplpSUYLugNeD3kdHjSeV+yobS79g8kDIDQK5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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