SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35c9a2b05bfe8188d47a6abb23594f0672b3e152c74c597ad62f463f6fbad42b' 
  AND token = 'L6RFihV8Abku0gHgSvfm/+TzBQErv0uy3HRMcjxHnLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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