SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e09fc26a662dc5b29d3676f387ee3fc486ae78c40c1ae9f7a5db21f2db3cd394' 
  AND token = 'lfbesE0r0pzwkPr8PNg1oqaFMzyGtFybGeQUg/ElyCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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