SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '240b96a5b10f40a4e626d17c5e26d64264abade45fab7dd194e9bb5823da7736' 
  AND token = '62bcEQ8mYQBoW2t6UqfXoG7P6BDs3HDHLZTJmQfB/Fw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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