SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e400babfd1434c9924a795aa52ecd8565d619cce2894c65dd2a147ba42cee50b' 
  AND token = 'wB1vChArczfH0CgVny5NlukmOhAIrpffwCHo2Uvigks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}