SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48537046f91c5b0113721d9995bd28dbcbc2ec4465035db0dc820b1de3a7e50f' 
  AND token = 'A/XXZxib1uyREPYcnktwa0eDlEMLOJOwz/D81tAY7dM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}