SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c2dea7a569a9a31169c9e2030a5e581dfb925b4c871dca621b7906c0db40c1f' 
  AND token = 'SoVab9yu3rY2jpwriT5bx49dXQeFMdANX4biVSupjsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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