SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '908997bfd038cdade7d5226e858a41b4ef458546cade1bcd6987caee1cf4048b' 
  AND token = 'l7EvN6Oz5ebk96j/p0XFvQKUY1O3jIPuXLu7/TsX1Q4=' 
  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"
    }
  }
}