SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2e7d11c1f2d1ef6f1a2a731ab2bfd62ba89f1709b414df1b7bc1f5466d1f553' 
  AND token = 'hpIlpkj1M49IRkDPJtlZTMsFBxBrVxiLTmaHMudPSck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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