SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f62c02aaad2dfee716bd9ee136172c88bd1686cab2079e782af86ad6b373cf3' 
  AND token = '2nYQvgAVKkgNhn0MCKEpis8XQ0DAq2u01h6DP1GY4qg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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