SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64219d66ac83dbdb9748b33d4464a322935465969437bb3236a508fdb90fc52d' 
  AND token = 'c+J2qJAsD+pKSjIN8odigBxprUV2WST1wvjWzBhJFC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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