SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb58110d535865e9e24c64b52ec38220aaaddac8711f7881edd0572e385414f0' 
  AND token = '8TFnj///lpyRhrBDjpy2oBPAuSEY6LupLO+LMXXQvNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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