SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '768c4704349b4fde308297bdcb410c3c33f045b0f8f90ab64f6a7d8a5b60df8a' 
  AND token = 'PrbZvdC2wtNyigKqD+WHvChEvuM81XcTNaHR6DuV/VY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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