SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df39c04a7ef710eccc0b82c71c0b011c04443e3735dbcbcc4672af5f628983df' 
  AND token = 'WLO6LLOrTtO1ZxeP92OFtAafx3eLcNcWyAJWw/MLmkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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